Circuit control means



1949. C H. A. ZIOLA 7 2,483,866

CIRCUIT CONTROL MEANS Filed Sept. 21, 1946 I 9 2 Sheets-Sheqt l 35. J z A? 1' Qoaec! or CURRENT OURCI OF CURRENT 227- 2 BY M A f fgfw Oct. 4, 1949. I H A. ZlOLA 2,483,366 I CIRCUIT CONTROL MEANS Filed Sept. 21, 1946 V v 2 Sheets-Sheet 2 J I L I /42 l I /Z7 /28 L l by 4/ Q @3 SUI/RC E 0F (TU/B654 T 3 1 N V EN TOR.

BY fl AM M Patented Oct. 4, 1949 CmCUI'r. CONTROL MEANS I -Henry Ziola, Mansfield, Ohio, assignor to Dominion' Electrical Manufacturing, Inc., a cor- .j "poration of Ohio Application September 21, 1946, Serial No. 698,497

I 1 My invention relatesl to circuit controls for controlling the energization I of resistance elements in heating. devices.

One of the objects of my invention is the pro-' vision of a circuit control ton controlling the energization of the various resistance elements in aheating d-evice to avoid drawing excessive watts energy from a source of electrical energy.

Another object of my invention is the'provisio'n of a heating device having heater units with resistance elements therein and a circuit control with a thermostatic switch means cooperating therewith for controllingthe' energization of the resistance elements. I j

Another object of my invention is the provision of a heating device having'more than one heater unit with a circuit control for controlling the energization of the resistance elements'of the heater units whereby energy cannot be used at a rate greater than ther'ate at which the energy may be safely supplied fromfanel'ectrical source ofenerey. Z, v f 1 Another object of my invention is the provision of a circuit cont'rol'fo'rf a heating device whereby at least a resistance element of one heater unit may be connected to as'ou'r'ce of electrical energy and whereby at least one resistance element in each of at least two heater units may be connected" to the source of electrical energy.

Another object of my invention is the provision of a circuit control for a heating device whereby at least a resistance element of one heater unit may be connected to a source of electrical energy and whereby at least one resistance element in eachof at least two heater'units may bacon- 1 nected to the source of electrical energy, with the total energy drawn by the-heating device being less than a safe predetermined value.

Another objector my invention is to provide,-

resistance elements ina heating device toobtain various heats therefrom.- l

Another object of my invention is to control the energization of the resistance elements in the heating units of a heating device whereby one heating unit may use a predetermined amount of watts energy or the heating unitsmay use variable amounts of energy with the total energy used never greater than-the predetermined 2 Claims. (Cl. 219-) amount of watts energy which may safely be drawn from thesource of electrical energy. o

Other objects and a fuller understanding of my invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, :in which:

Figure 1 is a circuit diagram illustrating the features of my circuit control; s

Figure 2 is amodification of'the circuit diagram of Figure 1; and s Figure 3 is a circuit diagram illustrating a modification of my circuit control.

In Figure l of the accompanying drawing, I have illustrated symbolically the wiring diagram of my electrical heating device, which may be incorporated into a two-plate hotpl-ate for cooking. My heating device is designed for safe use in the average home. Household heating devices generally are not safe if they can draw a load of energy greater. than 1650 watts at volts from the outlet wall socket. My heating device may be used in the average home without fear of overloading the 115 volt electrical circuits or overheating the heating device. stood that I do not wish to limit the scope of my invention to hot plates or to the specific values used in this description, but am using them to better illustrate the features of my invention.

I have designated my heating device, for descriptive purposes, as having :a heater unit I0 and a heater unit I I. As is best illustrated in Figure 1, the heater units l0 and I I may be combined into a single heating device by a suitable casin I2. The heater unit ID has a resistance element 38 and a resistance element 39. Similarly, the

heater unit II has a resistance element 36 andal resistance element 31. These resistance elementsare connected by suitable circuit connectors Hi to 2| inclusive, to the lines 21 and 2-8 of a source of electrical energy l3. m

A circuit control l4 controls the energization of the resistance elements 36 and 31 in the heater unit H and the resistance elements 38 and 39 in the heater unit In. The circuit control It, as is herein described, includes single pole single throw Switches 32, 33 and 34, and also a single pole may be used for heating devices for other pure It is underposes, in my household hot plate heating device, which is designed to operate on 115 volts, I use a 1650 watt resistor for the resistance element 35, a 1070 watt resistor for the resistance element 3'1, a 650 watt resistor for the resistance element 38, and a 350 watt resistor for the resistance element 39. It can readily be seen that since the 1650 watts energy consumed by the resistance element 36 is the same as the maximum safe watts energy which can be drawn from the source of electrical energy I 3, that by connecting the heater units I I! and I I to the source of electrical energy I 3 at one time, a dangerous overload can be caused on the source of electrical energy I3. My circuit control I4 which includes switches 32, 33, 31 and 35 allows me to use either one or both of the heater units without fear of overloading the source of electrical energy.

Referring again to Figure 1, the circuit cennector It connects one side of the resistance element 38 'androne side of the resistance element 39 to the line 280i the source of electrical energy [3. The circuit connector I6 connects the other side of the resistance element 39 to one terminal of the single .pole single throw switch 32. circuit connector I! similarly connects the other side of the resistance element 38 to one terminal of the single pole, single throw switch '33. The other terminals of the switches 32 and 33 are connected by the circuit connector I8 to a ,I

contact terminal of the single pole double throw switch 35. The switch 35 has a movable switch member 23 connected to the line TI of the source of electrical energy I3. This switch member 2 may be closed against the contact terminal 25 to energize the resistance elements 38 and 33 of the heater unit In when switches 32 and 33 are closed.

The resistance elements 36 and 31 in the heater unit 'II are connected together on one end thereof and by the circuit connector 1'9 to a contact terminal 26 of the single pole double throw switch 35. The switch member 24 in the single ipole double throw switch 35 may be closed against the contact terminal 26 to connect one side of the resistance elements 36 and 31 to the line 27 of the source of electrical energy I3. The other side of the resistance element 36 is connected by the circuit connector 20 to one terminal of the switch 34. The other terminal of the switch 34 is connected to the line 28 of the source of electrical energy I3. Similarly, the other side of the resistance element 31 in the heater unit I! is connected by a'circuit connector 2I directly to the line 2'! of the source of electrical energy I3. I have installed a thermostatic switch 30 in the connector I3 which connects the resistance elements 33 and 31 in the heater unit II to the contact terminal 26 of the single pole double throw switch 35. The thermostatic switch '39 operates when the temperature of the heater unit II reaches a predetermined value to open the circuit connector I3. By using this thermostatic switch 38, I am able to quickly heat the heater unit II with the 1650 watt resistance element 36 to the predetermined temperature and then keep the heater unit II at that temperature with the resistance elements 36 and 31 in series. The resistance elements operating in series draw less than the 1650'watts energy from the source of electrical energy.

In operation, when the switch member '2 of the switch is closed against the contact terminal 25 and the switch 32 is closed, the resistance element 33 in the heater unit I0 is in cir- The L cuit, thus drawing 350 watts from the source of electrical energy. When the switch member 24 of the switch 35 is closed against the contact terminal 25 and the switch 33 is closed, the resistance element 38 in the heater unit I0 is energized by the source of electrical energy I3, thus the heater unit I0 is drawing 650 watts energy. When both switches 32 and 33 are closed the heater unit I!) is drawing 10D0 watts energy, which is the maximum the heater unit II] can safely draw from the 1650 watt source of electrical I3.

When the switch 34 is closed, the resistance elements '35 and 31 "in the heater unit II are in series acrb's'sthe source of electrical energy, thus the heater unit II is drawing approximately 650 watts energy tram the source of electrical energy. When the switch 34 is closed and the switch member 24 is closed against the contact terminal 26 of switch 36, the resistance element 36 is drawing 1 650 watts through thermostatic switch 30 from the source or electrical energy l3. As soon as the temperature of the heater unit 'I'I reaches a predetermined value, the thermostatic switch 30 opens, thus causing the resistance elements 33 and 3! to be in series. When the resistance element-S 36 and 31 are in series the heater unit -II will draw about 650 Watts energy.

At no time "can there be over 1650 watts-drawn by either the heater unit N, the heater unit H, or they two heater units I'D and 'II acting simultaneouslyandin parallel from the source of electrical energy I3. The heater units 10 and II operate simultaneously when the switch member "24 is closed against the contact terminal 25 of switch 35 and "when the switch 3'4 is closed. With these switches 34 and "35 in this position, and with switches 32 and 33 'Closed, the heater unit III will draw a total of 1000 watts energy and the heater unit II will draw a total of 650 watts energy. The resistance elements 36 and 31 of the heater unit II are in series across the source of electrical energy I3 when the heater units are operating simultaneously.

In Figure '2 of my drawing, I have illustrated a modification "at my electrical heating device. In this modification, I have inserted a thermostatic switch 3I inseries with a resistance element, in the heater unit f0. When the heater unit in is heated to a predetermined temperature by the resistance elements 38 and 39 the thermostatic switch I automatically opens to disconnect the assistance element 39 from the circuit. 133' using this thermostatic switch 3|, the resistance element 39 may be used as a booster element. That :is, it may be used to quickly heat the heater emit III to the desired temperature aitcr \which only the resistance element 38 keeps the heater unit at that temperature.

lmEigure .3 mi mydrawing :1 illustrate a modification of my circuit control. In this modificationithe'circuit @ontrol H disconnects the resistance elements entirely :tromthe source of electrical energy. The modified @ircuitcoritrol 'I'l com-v prises the single pole double throw imaster switch 35, a rotary gang-"swiwh ZIIII ior the heater iunit in and a r6tary switch l44 for the heater unit II.

The rotary switch MD has a cam mechanism I32 foroperat'ingthe switch 32, abazm mechanism I33 *for operating the switch 33 *an'd acam mechanism 2151501: Operating a Switch H5 in the congang switch is a four-position switch. These positions have been labeled, 01?, Low, Medium and High. To hold the switchin any one of these the switch I43 in that it has a cam mechanism I34 which operates the switch 34 and a switch I2I in the connector 2I. The rotary switch III has an on position and an off position. When the switch is rotated to the on position both switches 34 and I2I are closed, thus connecting the resistance elements 36 and 31 in the heater unit I l in series to the source of electrical energy. When the switch is rotated to the off position both switches 34 and I2I are open.

The operation of my modification illustrated in Figure 3 and using rotary switches is very similar to that of Figure 1. With the rotary switch M0 in the off position the cam mecha nisms hold all the switches 32, 33 and H5 open, thus the resistance elements of unit ID are entirely disconnected from the source of electrical energy.

With the master switch closed to energize the heater unit In and the rotary switch I40 in the low position the cam l 32 permits the switch 32 to close and the cam 2I5 permits the switch .I It to close. The resistance element 39 is connected to the source of electrical energy at this time.

With the master switch closed to energize the heater unit Ill, and the rotary switch I40 in the medium position, the cam I33 permits the switch 33 to close and the cam 2I5 permits the switch M5 to close. The resistance element 38 is connected to the source of electrical energy at this time.

With the master switch closed to energize the heater unit II) and the rotary switch I40 in the high position the cam I32 permits the switch 32 to close, the cam I33 permits the switch 33 to tion, the rotary switch I4I may be closed to connect the resistance elements of the right heater unit I I in series to the source of electrical energy.

With the master switch closed to energize the heater unit I I only the heater unit II can be energized. When the rotary switch MI is turned to the on position, the resistance element 36 is connected to the source of electrical energy. As

soon as the heater unit II reaches a predetermined temperature the thermostatic switch 30 will open to connect the resistance elements 36 and 31 in the heater unit II in series to the 115 volt source of electrical energy or household outlet.

As with my preferred circuit control illustrated in Figures 1 and 2, my modified circuit control illustrated in Figure 3 provides a heating device which has a variety of heats. At no time, however, can the heat exceed a predetermined quantity. The heat is limited by the watts energy which may be drawn from the source of electrical ferent resistance elements of the heating units to obtain these difierent heats in the heatingv units and at the same time prevents more than.

1650 watts energy being drawn from the 115 volt source of electrical energy.

Although I. have described my invention with a certain degree of particularity in its preferred form, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spiritand the scope of the invention as hereinafter claimed.

What is claimed is:

1. In an electrical heating device, a first and second heating unit each including a first and second heating resistance element, a circuit means for connecting the resistance elements of said units to a source of electrical energy, circuit control means in said circuit means and controlling the energization of said resistance elements, said circuit control means comprising, a first thermostatic switch disposed in the first heating unit and connected in series with the first resistance element thereof to effect energization of said first resistance element when the first heatin unit is below a predetermined temperature, switch means including a plurality of contact elements arrang'eable in a first position to connect the first resistance element of the first heating unit and the first thermostatic switch connected in series therewith in parallel with the second resistance element of the first heating unit to the source of electrical energy and also to connect the resistance elements of the second heating unit in series to the source of-electrica1 ener y, said contact elements arrangeable in a second position to connect the first and second resistance elements of the second heating unit in series to the source of electrical energy, and second thermostatic switch means disposed with the second heating unit and cooperating with the said switch contact elements to effect the short circuit of one of the resistance elements of the second unit when the second heating unit is below a predetermined temperature and to effect the energization of the first and second resistance elements of the second heater unit in series when the second heating unitis above the predetermined temperature.

2. A circuit, control for controlling the energization of the resistance elements in the heater units of a heating device, said heating device having circuit connection means to connect the resistance elements to the source of electrical energy, said circuit control comprising first switch means, a second switch, a thermostatic switch, and a master switch interconnected with said first switch means, said second switch, and said thermostatic switch, said master switch and said first switch means when in a first position cooperating to connect a resistance element of a first heater unit in series with said thermostatic switch and to the source of electrical energy, said master switch and said first switch means cooperating to connect one resistance element of the first heater unit and the thermostatic switch connected in series therewith in parallel with another resistance element in the first heater unit and to the source of energy when the master switch is arranged in the first position and the first switch means is arranged in a second posienergy. The circuit control permits use of diftion, said master switch and said second switch source-oi electrical energy;

HENRY Ac REFERENCES CITED.

cooperating? to connect-- the resistance elements: of the second heater unit in: series: and to the: source of: electrical. energm. saith switches and; switch; means. cooperating: to connect: at least one of the resistance elements of; theflrstheaten 5 unit to the source at electrical. energy. amt to simultaneously connect the resistance; elements: of. the: second. heater in series and to the The following references-l are of reeord m the file of this patent:

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